THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

(COMMERCIAL BREAK)

[09:33:53] POPPY HARLOW, CNN ANCHOR: New video just in of these twin attacks on Tehran. You can see and hear shots pummeling Iran's parliament building this morning at the same time attackers went after a shrine in the city. ISIS now claiming the country's first major terror attack in seven years.

JOHN BERMAN, CNN ANCHOR: CNN's senior international correspondent Frederik Pleitgen, who's been to Iran several times, is following this for us.

These were very, very big attacks that happened there in central Tehran but also in the south of Tehran, and they certainly appear to be coordinated because both those venues are pretty far apart.

Now, what we know is that around 10:00 a.m. several gunmen managed to penetrate into the security perimeter of Iran's parliament and immediately went on a shooting spree. Apparently one of them was fairly - killed fairly quickly. Another one blew himself up with a suicide vest. The two others managed to take several hostages, but at some point were also overwhelmed. It's unclear whether another one of those also managed to blow himself up. But we know that both of them were killed as well.

That hostage situation actually went on for a very long time. And the interesting thing about that is that the session in parliament actually stayed in session for a while as that hostage situation was going on. Obviously, the area around there completely cordoned off.

[09:35:03] The other attack happened at the Imam Khomeini Shrine, which is really the religious center of Iran. It's a shrine for the founder of the Islamic Republic Ayatollah Khomeini. It's very, very important to the Iranians. So with this attack, you have the religious center and the political center of Iran that were both hit.

Again, ISIS claiming responsible for this. The Iranians are saying they're taking this very, very seriously, but they also are saying they are going to remain defiant in light of these attacks, guys.

BERMAN: All right, Frederik Pleitgen for us following the developments in Iran. Thank you so much, Fred.

Russia, this morning, firing back at an exclusive CNN report that U.S. officials believe that Russian hackers were behind a fake news report that has contributed to a crisis among its closest Gulf allies. Sources tell CNN that hackers planted a fake report on Qatar's state run media that made the government appear friendly to Iran and Israel.

HARLOW: That report is part of the reason why Qatar's neighbors, led by Saudi Arabia and the UAE, cut ties completely with the country. The Kremlin, this morning, saying, well, the story is, quote, "another lie."

Our crime and justice producer Shimon Prokupecz is live here with us.

This is a huge deal if a fake Russian news report led to all of this.

SHIMON PROKUPECZ, CNN CRIME AND JUSTICE PRODUCER: Well, that's right. Certainly what some U.S. officials believe, that Russia was behind this hack, this breach of the state news agency in Qatar. What's interesting is that the FBI is now there assisting the Qataris them the investigation. It was at the request of the Qatar that the FBI help them in the investigation and they're going to go through some of the hardware to determine exactly, you know, who was behind the breach and how they entered.

You know, U.S. officials tell us that they're not certain yet if this was Russians acting on behalf of some criminal organization or, in fact, this was the Russian government - that was sanctioned by the Russian government, and that's still under investigation.

HARLOW: And the meat of the reporting, the meat of the article was a critical one.

PROKUPECZ: Yes, it was pretty critical. It basically attributed remarks that turned out to be fake to the Amir of Qatar, basically critical of Donald Trump. But, you know, also talked about Iran and Israel. So it sort of fueled some of the fire that's been going on between the countries there.

HARLOW: All right, Shimon, thank you so much for the reporting.

And in just about 24 hours, former FBI Director James Comey will appear before the Senate Intelligence Committee. He is expected to publically rebut what the president said about their private conversations. It will be a block buster moment, one that Washington and the world will be watching closely.

BERMAN: We're joined now by Illinois Congressman Mike Quigley, a Democratic member of the House Intelligence Committee.

Congressman, thanks so much for being with us.

Before we get to James Comey tomorrow, we have Dan Coats today. REP. MIKE QUIGLEY (D), ILLINOIS: Right.

BERMAN: The current director of National Intelligence. And this morning "The Washington Post" reports that on March 22nd, two days after testimony from James Comey, that the president asked Dan Coats to intervene with the FBI to get them to back off the investigation into Michael Flynn. Can you confirm this report?

QUIGLEY: I can't because anything we've learned about that at this point in time would have been in a classified setting. I will say this, if true, it is part of the Trump administration's graduation here. Initially in this investigation what we saw was the White House delaying, distracting, deflecting. The claims that the Trump Tower was bugged by President Obama. The Nunes midnight excursion. Claims that all this was fake news. It graduates to the arguably obstruction stage when you hear stories like this of firing Director Comey for that FBI thing and love to hear the testimony tomorrow. Director Comey alleging that he was told not to investigate General Flynn.

HARLOW: So there's a number of things being looked at here. Obviously, was there any obstruction of justice? Also, was there any collusion?

On the collusion point, listen to what the top ranking Democrat on the Senate Intelligence Committee said to our Jake Tapper just a few days ago on that.

(BEGIN VIDEO CLIP)

JAKE TAPPER, CNN ANCHOR: Is there any evidence of collusion that you have seen yet? Is there?

SEN. MARK WARNER (D), VICE CHAIRMAN, INTELLIGENCE COMMITTEE: There is a lot of smoke. We have no smoking gun at this point. But there is a lot of smoke.

(END VIDEO CLIP)

HARLOW: All right. So you sit on the House Intelligence Committee. Do you agree with him, there's a lot of smoke, no smoking gun? Have you seen a smoking gun?

QUIGLEY: The way I've described it is, if it was a criminal investigation, you have probable cause to go forward. You don't have guilt beyond a reasonable doubt. The investigation is in its infancy. The House has yet to interview a single one of our over 20 witnesses we anticipate that would testify in front of us. So there's a long way to go. It is premature to say that, as we've heard with some, that people will go to jail. It's premature to say that there's no evidence of collusion.

BERMAN: So the issue - another issue besides collusion, as Poppy was saying, is obstruction. You used that word before. The thing is, is that Dan Coats put on a statement this morning that said he never felt pressured by the president. Even if this conversation happened, which he did not deny, he never felt pressured by the president to back off an investigation. James Comey, we understand, is not going to testify tomorrow that he felt like he was interfered with this investigation. He's going to lay out the facts. But if he felt there was obstruction, we're told he would have said something at the time. So James Comey didn't think there was obstruction. Dan Coats didn't think there was obstruction. Is there a there there?

[09:40:27] QUIGLEY: Well, in terms of, is there obstruction from a criminal point of view or just the fact it was the president's intent? Some of that's going to be dependent upon exactly how they testify. So let's see what they have to say.

I mean Director Comey is a straightforward matter of fact, but he does surprise you at times. Just remember the last time he testified in front of the House in public session, he announced for the first time the Justice Department investigation. He announced that the Russians attacked our democratic process to help one candidate, Mr. Trump, over the other, Mrs. Clinton.

HARLOW: We've got 20 seconds left. This is the only time we've learned that Comey will testify publically on this. You sit on the House Intelligence Committee. Are you going to be watching tomorrow, sort of wishing you had a shot at him?

QUIGLEY: I think he'll testify in front of our committee as well.

HARLOW: You do?

QUIGLEY: I will be there tomorrow to watch.

HARLOW: All right, well, thank you.

BERMAN: All right. Congressman Mike Quigley, thank you so much for being with us.

QUIGLEY: Thank you.

HARLOW: Our special coverage on the former FBI's director's testimony to the Senate Intel Committee begins tomorrow morning, 9:00 a.m. Eastern, right here.

BERMAN: All right, tomorrow what we thought was the big show, but today is pretty darn big itself. We're waiting for a Senate hearing where we're going to hear from the current director of national intelligence in the reports this morning that the president pressured him or asked him to get the FBI to back off the investigation of Michael Flynn. People wonder, was this obstruction? Big, major questions. Stay with us.

(COMMERCIAL BREAK)

[09:45:50] BERMAN: All right, it is some of the most highly anticipated testimony in decades. Fired FBI Director James Comey set to face the Senate Intelligence Committee tomorrow.

HARLOW: One person who reportedly will not be surprised by what Comey has to say. The special prosecutor in charge of the investigation, that is Bob Mueller. According to Politico, Mueller's team has been in contact with Comey before he testifies. We know that is the case. Let's bring in Michael Zeldin. He's a CNN legal analyst and former federal prosecutor, who's also the former special assistant to Bob Mueller at the Department of Justice.

It is nice to have you here.

This week there is a ton, a ton going on in Washington. As I put it this morning, a crap ton going on in Washington. If you are Bob Mueller, you're running this investigation and you are waiting and watching for today's testimony that will begin in minutes and you're waiting for Comey tomorrow. What are you looking for?

MICHAEL ZELDIN, CNN LEGAL ANALYST: You want consistency from your witness. After all, Comey is Mueller's witness. If there's going to be an obstruction case, Comey is front and center in the making of that case. So he wants his witness to be on point, not verbose, you know, direct and concise in his answers.

HARLOW: Yes, no, yes, no.

ZELDIN: That's right. And really not giving his impressions. Really just saying, this is what happened. This was what was said to me. This is what I did in response to that. You guys in the audience, you can conclude what you will from that, but this is my testimony.

BERMAN: Well, along those lines, if that's what you're looking for, what are you afraid of? Is there any jeopardy in this for this special counsel, for Bob Mueller?

ZELDIN: Well, sure, because he, Comey, is going to be cross examined effectively. If you think of this as a witness, the Democrats, if you will, have their witness on direct exam and the Republicans have him on cross examine. And so you never know what's going to happen in cross examination. He could be asked a question and answer it in a way that's hurtful down the line to Mueller's case. So that's what Mueller has to be worried about. How is his witness going to perform?

I have a lot of confidence in Comey, but you never know, it's a fluid situation and he says things - he's said things before that have had to be corrected. So that's the risk for Mueller.

HARLOW: He has two sessions tomorrow. The public session in the morning, right during this show, by the way, you have to turn in, but he also has this closed session. And not to read his mind, you don't know what he's going to say behind closed doors, but what things may he be willing to talk about behind closed doors that he will not say in a public forum?

ZELDIN: I think behind closed doors he talks about the Russia investigation. The - not the collusion so much, although maybe a little bit, but really the interference stuff. Where was the investigation at the point that he left in terms of that? I think that's what is classified. I don't think they'll be talking about collusion so much. I don't for sure think they'll be talking about obstruction so much. It's really the highly classified information that just is not allowed to be said in public. BERMAN: So in addition to all of this, we learned overnight that the

current attorney general, Jeff Sessions, offered to resign. There was a huge amount of tension between the president and the attorney general over the fact that Jeff Sessions recused himself from the Russia investigation, tension about the travel ban as well. In the back and forth, Jeff Sessions apparently say, well, if you don't want me here, you know, I'll go away. You worked in the Justice Department. What's your take on this tension and how unusual it is?

ZELDIN: Well, it's interesting that you ask in the sense that - and you wouldn't know, but I was in the Justice Department when Deputy Attorney General Arnold Burns resigned over ethical lapses he felt that Attorney General Meese presented. Then the assistant attorney general resigned as well, Bill Weld. And so I was there for two resignations in two days because of these types of tensions. And it's a horrible place to work under those circumstances. And so the notion that Sessions is thinking about quitting or has tendered the possibility of resigning just sends shockwaves through the department and makes it hard in the sense to get up each morning and go to work, because you don't know what you're coming to work in.

HARLOW: Yes.

BERMAN: All right, Michael Zeldin, there is plenty of work to do there as well. Great to have you with us. Really appreciate your time.

ZELDIN: Thank you.

[09:49:49] BERMAN: Moments from now, the director of national intelligence, Dan Coats, he will testify before the Senate Intelligence Committee. The big question all of a sudden this morning, did the president pressure him to dismiss concerns about Michael Flynn. Stay with us.

(COMMERCIAL BREAK)

HARLOW: All right, moments from now, lawmakers on Capitol Hill set to grill the intelligence chiefs on the Russia probe and a whole lot more.

BERMAN: Yes. It comes just one day after the fired FBI Director James Comey, he will testify tomorrow. And amid all this, the president just announced his pick to be new FBI director.

Want to get right to CNN's senior congressional reporter, Manu Raju, on Capitol Hill.

Manu, Dan Coats, he will be there to testify. "The Washington Post" reports the president pressured him to back off the Michael Flynn investigation. What are you expecting today?

[09:55:02] MANU RAJU, CNN SENIOR CONGRESSIONAL REPORTER: Yes, that's right. In fact, he's going to make an opening statement on behalf of the four intelligence officials who will be testifying at this hearing. And expect those questions about what President Trump asked Dan Coats to do and whether or not he asked him in any way to back off that Michael Flynn investigation. Expect that to come right at the top, particularly when Mark Warner, the top Democrat on the committee, begins his questioning later in the round.

Now, the question is whether or not Coats will reveal anything. His spokesman put out a statement earlier this morning saying that he does not want to discuss these private discussions with President Trump. He says he did not feel pressured in any way to back off the investigation. The question is whether or not members of this committee will be satisfied. I had a chance to ask Ron Wyden (ph), who's a senior Democrat on the committee, whether or not Coats should in any way detail his conversations with President Trump and why he did not explicitly say that? He said that we should go wherever the facts take us. He would not say whether or not he wants Coats to go that far.

Now - but Coats is not the only one who's going to face some pretty intense questioning, as well as Rod Rosenstein. It's the first time he has testified publicly since the firing of James Comey and, of course, he wrote that memo that the White House initially pointed to that said that that was the reason why President Trump fired James Comey. The question will be whether or not Rod Rosenstein agrees with that in any way what the president did and whether or not that was the justification for firing and who told Rod Rosenstein to write that memo, whether he was directed by the president in any way. Whether or not Rosenstein reveals any of this publicly will be an interesting question because he has not done so in a private session with lawmakers saying that it is something that Bob Mueller, the special counsel, could presumably be looking at.

So a lot of questions today. All a prelude to the big hearing tomorrow. But one in which could reveal some new details about President Trump and what he's been telling his national security officials privately about this Russia investigation, guys.

Dana, to you. The man of the hour, in just three minutes, is Dan Coats. And this is a man who, in his testimony less than a month ago said when asked by Senator Gillibrand, you know, will you detail these private conversations with the president? He said not here. But if I am called in front of an investigative committee, I will tell them what I know and what I don't know. Well, he is now going to be in front of an investigative committee.

DANA BASH, CNN CHIEF POLITICAL CORRESPONDENT: That's right.

HARLOW: He's a seasoned politician. You've covered him extensively. What should we expect today? I mean full candor or some political maneuvering?

BASH: You know - you know, we'll see - first of all, when he gave that answer, it was like someone was sticking hot needles in his eyes. He was so pained when he was - when he was talking about it. And, look, this is somebody who was a member of the U.S. Senate for a long time, retired, said, I'm done with public service, and was lured back by Republican pooh-bahs (ph) who thought that were right, that he - that he was the only way to get a Senate seat back in Indiana, and then he came back.

So he is somebody who is a dedicated public servant. He is a conservative Republican. He certainly is a political expert and politically sophisticated, but I can see him being somebody who, you know, is not going to play political games because he wants to be on the up and up when - with regard to something that is so incredibly critical and sensitive, like the president of the United States suggesting to him in his role as director of National Intelligence that he should potentially help sweep something under the rug.

BERMAN: Nia-Malika Henderson, the hearing today is actually a very serious hearing about the security act, you know, reauthorizing section 702, which allows for surveillance of foreigners and, of course, it has - gets into the whole unmasking thing. So there's a lot of serious discussions to be had here. That said, Democrats put us in their minds right now. How hard do you think they will push, even if Dan Coats, the director of National Intelligence, says I'm not going to talk about this?

NIA-MALIKA HENDERSON, CNN SENIOR POLITICAL REPORTER: Very, very hard. I mean they see this as a real moment. You've got, you know, some potential stars who are on this committee. People like Kamala Harris. You imagine that these people want to make a moment and make their mark on this investigation. Burr has said he obviously wants to figure out if they can make it about FISA and renewing FISA, which is - expires at the end of this year, but he knows that this is going to be a wide-ranging hearing.

It will be interesting, I think, in terms of Coats. He used to be on this committee, right?

BASH: That's right.

HENDERSON: How do the Republicans treat him? It's one thing for Republicans to treat Comey a certain way and essentially try to undermine his credibility, but this is a member of the - was a former member of their club, right, the Senate club. So it will be really interesting to see how they engage with Coats, whether or not they try to stay on FISA in talking to him. So that will be something interesting to watch as well.

HARLOW: You know, in terms of Rod Rosenstein, and Manu's reporting this is going to be the first time that he publicly expresses all of this, what the memo was for, who told him to write the memo, et cetera. Gloria, the White House completely changed their narrative within that 24-hours, first using the memo as justification for firing Comey, then you would think there was quite a back and forth between Rosenstein and the White House and then they completely changed their narrative. Now he's going to say what it is.